The present invention relates to a laser driving circuit utilizing a laser diode (semiconductor laser) in which the intensity of the laser beam emitted by the laser diode is regulated.
Conventionally, a laser diode has been used as a light source for emitting laser beam in a laser beam printer and the like. In such a laser beam printer, a laser driving circuit having an APC (Automatic Power Control) function is generally employed in order to control the intensity of the laser beam to be a predetermined value.
There are a plurality of types of laser beam printers, which have photoconductive members having different characteristics. Thus, it is necessary to design a plurality of laser driving circuits each being capable of emitting a desired intensity of laser beam.
Further, there are individual characteristic differences among the same type of laser diodes an/or photodiodes. Accordingly, each laser driving circuit is required to have an adjusting circuit for compensating for the above-described individual characteristic differences.